Another trinket from my workshop 
Recently updated a web-control I’d developed circa 2012-2014ish for a client developing navigational software, that happened to need text-to-speech regardless of, if the user had access to the internet; and paid APIs are TOO expensive for large use. (Yes, the web-application ran on ‘localhost’). Google now blocks the public translate.google.com API for TTS, that was available until the beginning of 2016. After some major updating, the control now attempts to load the speech synthesizer found on the user’s system. If that’s not found, it attempts to access the Chrome Speech Synthesizer libraries (works in any ‘modern’ browser) from the user’s system if Chrome is installed. Last resort, if neither a native synthesizer nor the Chrome library can be found locally, it will lastly attempt to load the Chrome Speech Synthesizer libraries from the internet…which, if internet is available at startup, it will load the internet libraries for use in case the internet “goes down,” and default to the local speech synthesizer until that happens… for full uninterrupted text-to-speech online & offline. There are 46 voices that support every major and not-so-major language.
Enjoy!
Download Control at: https://www./download/xdswebtts-web-text-to-speech/
